import turtle

# 创建一个窗口和画笔
screen = turtle.Screen()
pen = turtle.Turtle()

# 设置画笔速度
pen.speed(2)

# 绘制正方形
for i in range(4):
    pen.forward(100)
    pen.right(90)

# 点击关闭窗口
screen.exitonclick()